1. Field of the Invention
The present invention relates to a printing apparatus, and is particularly preferable for maintenance of a printing head used on an inkjet printing apparatus and for performing a printing on a printing medium by ejecting ink.
2. Description of the Prior Art
A printing apparatus is known that comprises a primary power-turn-on means for bringing a state to physically supply electric power to the apparatus (that is, a hardware-power-on state) and a secondary power-turn-on means for bringing the printing apparatus into a state where functions thereof are executable (that is, a software-power-on state).
In an inkjet type printing apparatus for printing on a printing medium by using a printing head (i.e., an inkjet head) for ejecting ink, provided is recovery processing means for forcedly ejecting ink through an ink ejection opening in order to eliminate clog and so on causing an ejection failure or non-ejection state at the ink ejection opening provided at the printing head and to maintain favorable ejection performance. This recovery processing means has, for example, a cap member for capping a face on which ejection openings are formed of the inkjet head (the face will be referred as xe2x80x2the ejection opening forming facexe2x80x2, hereinafter), suction means for suctioning the inside of the cap and a member for wiping the ejection opening forming face.
In the above-mentioned inkjet printing apparatus, when the software-power-on state is brought about for the first time after the hardware-power-on state, in the accompanying software-power-on processing, a recovery processing as a maintenance action for the inkjet head, that is, recovery processing through suctioning is executed unconditionally. This means that suction recovery processing of the inkjet head is always executed when the hardware power supply is turned on, because the maintenance state of the inkjet head is not known when it was executed before the hard power supply was off previously.
The recovery processing for forcedly ejecting ink from the inkjet head by means such as suction is an indispensable processing for eliminating ejection failure of the inkjet head due to clog or the like at the ink ejection opening and for maintaining ejection performance. However, there is a problem that ink consumption is increased by the recovery processing.
It is an object of the present invention to recognize a state before the hardware power supply was turned off the last time and to reflect the recognition in a software-power-on processing at the present time.
It is another object of the present invention, in the inkjet type printing apparatus for printing on a printing medium using an inkjet head, to maintain ejection quality of the inkjet head while effectively suppressing increase in ink consumption through recovery processing of the inkjet head by judging necessity of maintenance processing of the inkjet head when the software power supply is on, based on the maintenance state of the inkjet head before the hardware power supply was off last.
In a first aspect of the present invention, there is provided a printing apparatus for performing printing on a printing medium by using a printing head, comprising:
means for turning on/off a secondary power supply to bring the apparatus into a state in which a function is executable after a primary power source for physically supplying power to the apparatus is turned on;
means for counting the number of times that the secondary power supply is turned on; and
means for holding the count value even in a state where the primary power supply is turned off.
In a second aspect of the present invention, there is provided a printing apparatus for performing printing on a printing medium by using a printing head, comprising:
means for switching between a state in which operation of the apparatus is made possible and a state in which operation of the apparatus is not made possible, in a state where power is supplied to the apparatus;
means for counting the number of times that operation of the apparatus is made possible by the switching means; and
means for holding a count value of the counting means even in a state where power is not supplied to the printing apparatus.
In a third aspect of the present invention, there is provided a printing system comprising a printing apparatus for performing printing on a printing medium by using a printing head and an image data supplying apparatus for supplying an image data to be printed to the printing apparatus, the system comprising:
means for turning on/off a secondary power supply to bring the apparatus into a state in which a function is executable after a primary power source for physically supplying power to the apparatus is turned on;
means for counting the number of times that the secondary power supply is turned on; and
means for holding the count value even in a state where the primary power supply is turned off.
In a fourth aspect of the present invention, there is provided printing system comprising a printing apparatus for performing printing on a printing medium by using a printing head and an image data supplying apparatus for supplying an image data to be printed to the printing apparatus, the system comprising:
means for switching between a state in which operation of the printing apparatus is made possible and a state in which operation of the printing apparatus is not made possible, in a state where power is supplied to the printing apparatus;
means for counting the number of times that operation of the printing apparatus is made possible by the switching means; and
means for holding a count value of the counting means even in a state where power is not supplied to the printing apparatus.
According to the present invention, by providing counter means for counting the number of times when the secondary power supply (software power supply) is turned on and means for maintaining the count value even during the state where the primary power supply (hardware power supply) is off or power supply to the apparatus is stopped, the apparatus state till the hardware power supply was turned off last is reflected in the processing of the software power supply at the present time.
In the case that the present invention is applied to the inkjet type printing apparatus, it is judged whether or not the count value is more than or equal to a predetermined value when the software power supply is on, and if an affirmative judgement is made, recovery processing of the inkjet head, for example, recovery processing by ink suction through an ejection opening is executed. Further, there is provided a function to clear the count value and storage contents of storing means when the recovery processing is executed and to prevent the count till the hardware power supply is turned off.
That is, when the software power supply is on after the hardware power supply was turned on, only for the first time when it is judged that the count value for counting the times of software-power-on without recovery operation of the inkjet head becomes more than or equal to a predetermined number, the recovery operation is executed. When the recovery operation is executed, the count value is cleared and the count value is not renewed till the hardware power supply is turned of f even if the software power supply is turned on/off. Also, as the count value is maintained in a non-volatile memory and the contents thereof are retained even during the hardware power supply is turned off. Therefore, increase in ink consumption due to recovery processing of the inkjet head is properly suppressed while maintaining ejection quality of the inkjet head, by judging necessity of maintenance processing of the inkjet head when the software power supply is turned on based on the maintenance state of the inkjet head before the hardware power supply was turned off.
In this specification, a word xe2x80x9cimagexe2x80x9d means the concept covering characters such as letters, numbers, symbols, etc. as well as images of patterns, pictures, photos, etc. in a narrow sense and also includes mixture of them.
A word xe2x80x9cprintxe2x80x9d refers to not only forming significant information, such as characters and figures, but also forming images, designs or patterns on printing medium and processing media, whether the information is significant or insignificant or whether it is visible so as to be perceived by humans.
The term xe2x80x9cprinting mediumxe2x80x9d include not only paper used in common printing apparatus, but cloth, plastic films, metal plates, glass, ceramics, wood, leather or any other material that can receive ink.
Further, the word xe2x80x9cinkxe2x80x9d should be interpreted in its wide sense as with the word xe2x80x9cprintxe2x80x9d and refers to liquid that is applied to the printing medium to form images, designs or patterns, process the printing medium or process ink.
The above and other objects, features and advantages of the present invention will become more apparent from the following description of embodiments thereof taken in conjunction with the accompanying drawings.